Free Auto Repair Advice by Certified ASE Technicians
How Do I Repair My Car?
/ How Do I Jump
Start My Car?
How to Jump Start Car Battery Using Jumper Cables
READ COMPLETELY BEFORE BEGINNING!
When a battery is dead a jump start is needed to troubleshoot the reason the
battery went dead. A dead battery condition can range from a car door left open
to the headlights being left on overnight. Low battery voltage is a common car
problem. As a battery ages it can lose the ability to store electricity resulting
in an insufficient flow of electrical energy to the starter. The starter is designed
to operate on a high amperage 12 volt system, when a starter is subjected to low
voltage or amperage (flow) it will cause the starter to not operate. To jump start
your car battery use a good quality jumper cable set. Inexpensive cables do
not work as well because a higher gauge wire (smaller diameter) is used in the construction
restricting the current flow from battery to battery.
Battery Jumper Cables
Basic Battery Jumper Cable Instructions
- Park the car that will be used as the jumper vehicle near enough for the
jumper cables to reach to the front of the car that is going to be jumped, and
shut off engine. (or were the battery is located, most vehicles are located
in the front, under the hood)
- With the engine off open the hood on both cars and connect the red jumper
cable connector on the positive (+ red) side of the battery of the car that
has the dead battery. Once the jumper cable end is attached slightly wiggle
the jumper connector back and forth to assure a good electrical connection.
Next repeat this procedure to the battery in the jumper car so both red jumper
cables are connected to their respective batteries. (Do not allow the black
and red cable ends to connect at anytime)
- Then attach the black connector of the jumper cables to the negative (-
black) terminal of the car with the dead battery. Next, attach the remaining
black jumper cable connector to an engine accessory bracket such as an alternator
or air conditioner compressor mount away from the engine belt system. The reason
we do not connect the last connector at the negative battery terminal is to
avoid sparks at the battery. Sparks on or near the battery can cause the battery
to explode. While explosions are rare they will more likely occur to a battery
that is low on charge or a battery that has just been charged this is why the
final circuit connection is at an engine ground source.
- Next, step back
from both hood areas of both vehicles. With all the accessories turned off and
both cars gear selectors in park with the emergency brake on start the engine
of the jumper car (car with good battery) and allow to idle for about 5 minutes.
Then, manually increase the engine speed to a little faster than idle speed
(about 1500 RPM) by holding the accelerator down slightly for about 10 minutes.
You are creating a charging system for the dead battery by the alternator of
the car that is running.
- Next, crank over the car's engine with the dead battery, it should crank
over and start. Once the engine has started manually increase the engine speed
to about 1500 RPM and hold for about 10 minutes. While the car that had the
dead battery is running shut off the engine of the jumper car, and remove the
black jumper cable end. Then, carefully remove the back jumper cable connector
from the now charging dead battery. Next, remove the red jumper cable connector
from the jumper car and close the hood. Finally, remove the remaining jumper
cable connector and close the hood.
- While the dead battery car is running inspect the charge inductor light
on the instrument cluster. If it is illuminated the
charging system
is having a problem and needs to be checked. If repeated jump starts are required
and the charging system has check out ok the battery has failed to hold a charge
or there is an electrical draw in the system.
- If you have followed this procedure and the vehicle still has not started
the battery may have failed (shorted) internally and cannot be jump started
or you have a
failed battery connection and further troubleshooting is required.
Related Inspections
Check
Battery Cable Corrosion - The battery cables are used to transfer electrical
power from the battery to the starter. Battery acid causes corrosion inside the
battery cable and will inhibiting electrical flow. To check for this condition look
for bulges near the top of the cable, these bulges indicate corrosion expansion
caused by the chemical reaction between the acid and copper wire. Remove the failed
battery cable to replace with new unit, then
check charging system to
ensure proper operation.
Rapid Clicking Sound When Cranking - The starter is designed to operate
on a high amperage 12 volt system, when a starter is subjected to low voltage or
amperage (flow) it will cause the starter to engage and disengage rapidly producing
the rapid clicking sound. To fix this problem a battery inspection or replacement
is needed. There are two reasons that a battery will not perform as it should, either
the alternator has failed allowing the batteries state of charge to become weak
or the battery has failed and replacement is required. Unfortunately to check the
alternator the engine must be running, so you must either jump start your car or
replace the battery to
check the charging
system. If the alternator output test is ok then the battery is bad and must
be replaced. If while driving the charge light indicator on the dash was not illuminated
and the battery is more than three years old the battery has probably failed.
Inspect Battery for Bulging - The battery supplies electrical power to
the vehicle, when a battery short circuits internally it can cause the car to lose
power and regain it back again. Inspect the battery; if the sides are bulging it
could have a warped plate that can short under certain conditions. The problem is
to check for this condition the battery needs to be disassembled which is very difficult.
This problem is rare but it does happen.
WARNING! Always wear protective eyewear, gloves and necessary
clothing before inspection or work begins. Never crank an engine over when you are
near the battery or engine. A battery is filled with acid that produce explosive
vapors that can ignite when extreme heat or a spark is present. A battery could
have residual acid on the outside casing so use caution when handling a battery
and the surrounding area. Apply baking soda to neutralize any suspected acid residue
before work begins.
How Do I Repair My Car?
/ How Do I Jump
Start My Car?
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